Invitations to Sen. Jim DeMint’s (R-S.C.) presidential candidate forum will only be given to Republican contenders polling at 5 percent support or higher in the RealClearPolitics.com poll average as of Aug. 22, which could lead to the exclusion of some big names.

Luke Byars, one of the organizers of the Palmetto Freedom Forum, set for Labor Day in Columbia, S.C., confirmed the criteria Wednesday during a telephone interview with Roll Call. And although Thursday’s GOP debate in Iowa and this weekend’s straw poll could markedly affect presidential primary polling, the current RealClearPolitics.com average means some notable candidates would be excluded if invitations were being determined now, including former Utah Gov. Jon Huntsman, former Speaker Newt Gingrich (Ga.) and former Minnesota Gov. Tim Pawlenty.

As of Wednesday afternoon, Huntsman, who most recently served as ambassador to China for President Barack Obama, wasn’t registering any support. Gingrich had a 4.1 percent average, and Pawlenty garnered 2.6 percent. Former Sen. Rick Santorum (Pa.), who registered at 1.8 percent, would also be excluded according to the invitation criteria as designated by the forum’s organizers.

“Until we get the polling, we’re not extending or accepting any invitations,” Byars said.

The Palmetto Freedom Forum is the brainchild of DeMint, a tea party favorite, and its organizers come from the ranks of his close-knit group of South Carolina supporters.

On the forum’s advisory committee are Byars and Kevin Hall, who is active in South Carolina Republican politics. Hall has been an aide to Sen. Lindsey Graham (R-S.C.). Also on the committee are Peter Brown, a member of DeMint’s finance committee for several years and a supporter of former Massachusetts Gov. Mitt Romney in 2008, and Barry Wynn, a former state GOP chairman and DeMint supporter going back to his first House bid.

The event is being sponsored by American Principles Project, a conservative 501(c)(3) organization founded by Princeton University Professor Robert George, who will share moderating duties during the forum with DeMint and Rep. Steve King (R-Iowa). The format calls for each candidate to take the stage separately and answer questions and discuss a range of policy issues for 15 to 20 minutes.

Byars said the forum came together “from the frustration DeMint felt watching [presidential] debates, where candidates only have 30 seconds to respond to questions — ‘the world economy is collapsing, what do you plan to do, time’s up.’”

Byars said the Republican presidential candidates have been approached about the event and made aware of the criteria and timing for the invitations, so that they have time to plan to attend if they qualify.

The most current RealClearPolitics.com average of all polls released July 17 through Sunday gauging national support for the GOP presidential candidates showed Romney in the lead with 19.7 percent, followed by Texas Gov. Rick Perry with 15.4 percent. (Perry is expected to announce his candidacy next week.) Rep. Michele Bachmann (R-Minn.) has 11.6 percent, 2008 vice presidential nominee Sarah Palin has 11 percent, former New York City Mayor Rudy Giuliani has 10.5 percent, Rep. Ron Paul (R-Texas) has 8.7 percent and wealthy businessman Herman Cain, of Georgia, has 5.9 percent support.